Satellite broadcast systems that broadcast high priority content directed at a relatively large region and simultaneously use spot beams to broadcast low priority content over sub-regions within the large region are known. The high priority content is sometimes referred to as a national signal that is be broadcast over, for example, the continental United States (CONUS) or across the European continent (PAN European). The low-priority content typically contains information directed to a particular sub-region such as local weather or traffic information, or the low-priority content may be directed to a specific ground receiver within the particular sub-region. In some instances, these low priority or sub-regional transmissions use different frequencies or polarizations to separate the low priority signal from the high priority signal, or separate the combined high and low priority signals directed to one sub-region from those directed to adjacent sub-regions. The regional signal may contain national content, i.e. the same content at different frequencies.
Transmitting low priority content at a carrier frequency different than the carrier frequency used to transmit high priority content undesirably uses more bandwidth than necessary to communicate both the high and low priority content. Also, configuring ground receivers to detect content at different frequencies or polarizations undesirably increases the cost of the ground receiver by increasing the hardware and/or software cost. Transmitting both low and high priority content at the same carrier frequency into one sub-region while transmitting other low priority content with the same high priority content in to an adjacent region can lead to low priority content loss or interference along the boundaries of the adjacent sub-regions.